http://en.wikipedia.org/wiki/Alternating_current

http://en.wikipedia.org/wiki/Air_conditioning

http://www.associatedcontent.com/

http://www.actransit.org/

http://www.acdelco.com/

http://www.acdcrocks.com/

http://www.howstuffworks.com/ac.htm

http://www.acmoore.com/

http://www.goodmanmfg.com/

http://www.acpropulsion.com/